Various electro-optical systems have been developed for reading optical indicia, such as barcodes. The barcode comprises a series of bars and spaces of varying widths and having differing light reflecting characteristics. Barcodes may be one dimensional (1D), i.e., a single row of graphical indicia such as a UPC barcode or two dimensional (2D), i.e., multiple rows of graphical indicia comprising a single barcode such as a PDF 417 barcode. Barcodes and are usually present on a label attached to an object.
Systems that read barcodes called barcode readers electro-optically transform the graphic indicia into electrical signals and then decode the electric signals into alphanumerical characters that are intended to be descriptive of the article or some characteristic thereof.
There are different types of barcode readers or scanners. The types include such as, but not limited to, pen or wand-type readers, handheld readers, and fix-mount readers such as, horizontal slot readers, vertical slot readers, and readers that have both horizontal and vertical slots, such as a bi-optic scanner. Also, there are different ways of using the readers to read a barcode. In the case of pen or wand-type readers an operator has to swipe the pen over the label in order to read the barcode. In the case of handheld readers the operator need not swipe the reader over the label, but must at least position the reader near the label. In the case of fix-mount readers or scanners, the reading is performed by laterally passing the object, containing the label, over the scanner's window (exit window). However, in some places like checkout counters of super markets where fix-mount scanners such as bi-optic scanners are used, items are often swiped across the exit window during check out. The items can be quite heavy or dirty or wet. Also, since the exit windows are usually made of glass or other material similar to glass, it is quite likely that the exit window will get dirty, scratched or damaged. This can adversely affect the performance of the scanner.
Accordingly, there is a need for a method, a system, and an apparatus for monitoring an exit window of a scanner.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.